Scroll-type machines are commonly used as compressors in both refrigeration as well as air conditioning applications due primarily to their capability for extremely efficient operation. Unlike reciprocating technology with many moving parts, a typical scroll compressor has one scroll orbiting in a path defined by a matching non-orbiting scroll, which is attached to a compressor body. The orbiting scroll is coupled to a crankshaft in orbit, which creates a series of moving or successive gas chambers traveling between the two scrolls. On the outer portion of the scroll, a pocket draws in gas, which is compressed as the gas moves through a series of successive, increasingly smaller, moving chambers until the gas is discharged through a central port in the non-orbiting scroll.
Scroll compressors depend upon a number of seals to create and define the moving chambers. To perform properly, the scrolls must not leak, wear out or fracture. The costs associated with machining can be quite significant due to the complex shape of the scrolls themselves, the machining of grooves, and the assembly of these components.
Typical powder metal scrolls are commonly assembled by forming two individual pieces, a baseplate having a scroll wrap and a hub, and joining them together to form a scroll component. One current method of joining the two pieces together uses a brazing process. While this process is adequate for producing the scroll components, it also results in a braze joint that is situated in a potentially high stress zone, subject to localized high stresses due to the bearing loads applied to the hub. Joints that are located in high stress zones are more prone to failure as compared to joints located in lower stress zones.